CHARACTERISTIC SELF-ACTION REGIMES OF ULTRASONIC BEAMS IN LIQUIDS

The kinetics of acoustical processes (self-focusing, self-induced transparency, self-induced opacity, and self-concentration of acoustic energy) are studied experimentally. The investigations are carried out in viscous liquids (triacetin and an 87% aqueous solution of glycerin) in the temperature range from -80-degrees-C to + 20-degrees-C at input intensities of the sound beam I(o) = 0.1 - 20 W/cm2 (the input diameter of the beam is 15 mm, and the frequency is 2 MHz. The conditions for the observation of each process are determined experimentally. Anomalies are noted in the temperature variations of the time tau-SIT for the onset of self-induced transparency and the rise time tau-st to the steady state in the relaxation interval of the investigated media.